Global Distribution of Non-algal Particles From Ocean Color Data and Implications for Phytoplankton Biomass Detection

• Published in: Geophysical Research Letters
• Main Authors: Bellacicco, Marco, Volpe, G., Briggs, N., Brando, V., Pitarch, J., Landolfi, A., Colella, S., Marullo, S., Santoleri, R.
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Istituto di Science Marine (ISMAR ), National Research Council of Italy, National Oceanography Centre (NOC), Universiteit Utrecht / Utrecht University Utrecht, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Istituto di Scienze dell'Atmosfera e del Clima Roma (ISAC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Arctic; North Atlantic; Phytoplankton
• Online Access: https://hal.science/hal-03505053; https://hal.science/hal-03505053/document; https://hal.science/hal-03505053/file/Geophysical%20Research%20Letters%20-%202018%20-%20Bellacicco%20-%20Global%20Distribution%20of%20Non%25u2010algal%20Particles%20From%20Ocean%20Color%20Data%20and.pdf; https://doi.org/10.1029/2018GL078185

International audience In the last few decades, phytoplankton biomass has been commonly studied from space. However, satellite analysis of non-algal particles (NAPs), including heterotrophic bacteria and viruses, is relatively recent. In this work, we estimate the backscattering coefficient associated with the NAP fraction that does not covary with chlorophyll based on satellite particulate backscattering coefficient and chlorophyll (b(bp)NAP). b(bp)NAP is computed at 100-km resolution using 19 years of monthly satellite data. We find clear differences in b(bp)NAP between northern and southern oceans. High b(bp)NAP values are found in the Arctic and Southern Oceans, the North Atlantic area influenced by the Gulf Stream current, as well as shelf regions (i.e., Patagonian shelf) affected by upwelling regimes. Low correlation between chlorophyll and backscattering prevents precise b(bp)NAP estimations in oligotrophic areas (e.g., subtropical gyres). These b(bp)NAP estimations lead to a reduction to half in satellite-based phytoplankton biomass estimates respect to previously published results. Plain Language Summary In the ocean, there are different seawater constituents that contribute to the inherent optical properties: Phytoplankton is a major constituent and one of the most studied in the last decade. Other important constituents are the colored dissolved organic matter and non-algal particles (NAPs). NAP includes (i) heterotrophic organisms such as bacteria, micrograzers, and viruses; (ii) detrital organic particles such as fecal pellets and cell debris; and (iii) mineral particles of both biogenic (e.g., calcite liths and shells) and terrestrial origin (e.g., clays and sand). This study is the first attempt to define the NAP from space, and its spatial variability, and how it contributes to refine the phytoplankton carbon biomass estimation. We estimate the backscattering coefficient associated with the NAP fraction that does not covary with chlorophyll from the satellite particulate backscattering ...